Influence of Intake Air Temperature, Nozzle Opening Pressure and Fuel Injection Timing on the performance of Variable Compression Ratio Engine fueled with Biobutanol and Pyrolised Waste Plastic Oil

Disposal of waste plastic materials is a challenge in today's scenario and disposal of waste vegetables and fruits are costing very high. This work is to use biobutanol from the waste vegetables and fruits along with pyrolyzed waste plastic oil to replace diesel. Various proportions of biobutanol (0-50%) and plastic oil (0-50%) are prepared and tested for solubility and properties. The obtained properties are compared with diesel engine fuel base properties to select a blend that possesses closer properties. The chosen blend is tested for performance in various intake air temperatures (50, 75 and 100°C); one of the temperatures among the three which is producing higher thermal efficiency is considered for further testing. Other parameters nozzle opening pressure (190, 200 and 210 bar), Fuel Injection Timing (23, 26 and 29° before top dead centre) and Compression Ratios (16: 1, 17.5:1 and 19:1) are tabulated with respect to L9 Orthogonal array cum Taguchi method to arrive at optimal parameters combination. These parameters are deployed and the chosen blend is tested for various load conditions for performance. The results of the properties depicted that 85% of plastic oil and 15% of biobutanol blend is found suitable to replace diesel. The intake air temperature of 75°C is producing the highest thermal efficiency among the three intake air temperatures. The optimal level of the other three parameters is a 19:1 compression ratio, 26° before the top dead centre of fuel injection timing and 210 bar of the nozzle opening pressure with respect to the thermal efficiency and oxides of nitrogen emissions from the engine when fueled with the chosen blend. This produces marginally higher carbon monoxide and hydrocarbon emissions at low brake power conditions lower than 50% of rated power. The cost of the chosen blend works out to 0.82 dollars per litre against 1.21 dollars per litre in India.